1. Technical Field
The present invention relates to a test apparatus and a test method to test a device under test (DUT). More particularly, the present invention relates to a test apparatus and a test method to test a DUT to which a reference voltage of a predetermined high voltage is supplied.
2. Related Art
In recent years, the demand for High Voltage Integrated Circuit (HVIC) that outputs a signal with a high voltage has been on the rise. The HVIC is used in a motor controlling device of an electric vehicle, for example.
The HVIC is a device outputting a signal that has a predetermined amplitude with, for example, approximately 0 to 2 kV being used as a reference voltage level. To test the HVIC, a test apparatus supplies a reference voltage of a high voltage (approximately 0 to 2 kV) to the HVIC. Here, the test apparatus detects a data pattern of the output signal and judges whether the device under test (DUT) is good or bad based on the data pattern.
If the test apparatus does not apply a normal reference voltage to the HVIC, the test apparatus can not accurately measure the level of the output signal from the HVIC. A conventional test apparatus does not have means for measuring a reference voltage of a high voltage, and therefore can not accurately test a DUT. As such means for measuring a high voltage, a comparator or the like which can withstand a high voltage is additionally required. This indicates a high cost.
In view of the above, an advantage of some embodiments of the present invention is to provide a test apparatus and a test method which can solve the above problem. This advantage is achieved by combining the features recited in the independent claims. The dependent claims define further effective specific example of the present invention.